The purpose of this review is to describe in detail a new, specific, nuclear medicine imaging procedure in the field of oncology. Although the history of radioimmunoscintigraphy is not so short, the greatest advances in the realization of this idea have been made during the last two decades. The time has come for radioimmunoscintigraphy to became a standard procedure in the diagnosis of malignant as well as non-malignant diseases. Except some historical facts about the development of radioimmunoscintigraphy, this review also shows all the complexities of the problem which had to be resolved before a good idea was effectively realized. The authors have tried to present, to a reasonable extent, all problems in connection with the selection of radionuclides, antibodies, methods of labeling antibodies, and imaging procedure. In general, what interests medical professionals the most is the clinical application of radioimmunoscintigraphy as well as future development and improvements of this procedure as a step of radioimmunotherapy--a new kind of treatment in oncology.